1.) when an event, person or thing is extremely awesome or legit.
2.) when someone eats bad food, i.e. from a school cafeteria, which leaves him or her with really runny shits that burn the anus lining and surrounding anal areas. May lead to severe irritation of the sphincter rim and potent gaseous emissions.
1.) Kirby's edge garding skillz in Super Smash bros are most definitely hot flows.
2.) Wow I seriously just shat fatty hot flows all over the bathroom stall. It must have been that filthy gyro.